Exp120-vnew.JPG

Objective

To synthesize a Ugi adduct from o-Vanillin, furfurylamine Boc-tryptophan and 1-pentylisocyanide.

Procedure

A solution of o-Vanillin (76.05mg, 0.5 mmol) and furfurylamine (43.7uL, 0.5 mmol )was prepared in methanol-d4 in a 1ml volumetric flask to form an imine. Then Boc-Tryptophan (152.17mg, 0.5mmol), and 1-pentylisocyanide (62.9uL 0.5 mmol) was added to the preformed imine.

Results

o-Vanillin
HNMR
CNMR
Furfurylamine
H NMR
C NMR
Boc-Tryptophan
HNMR
CNMR
1-pentylisocyanide
HNMR
CNMR
1-Butylisocyanide
HNMR
CNMR
120A
11min
23min
32min
36min
48min
1h 4min
1h 34min reaction 88% complete towards imine.
120B
11min
18h

Discussion


The imine conversion was almost to 90% complete after 94min. However even after 18h of the acid and isocyanide addition not all the reactants have been converted to the product. The reaction is slow. Moreover no certainty could be established about the presence of a Ugi product in 18h NMR.

Conclusion

No Ugi product isolated

Log

2007-08-15

17:20 Made up a solution of o-vanillin and furfurylamine in CD3OD in a 1ml volumetric flask, transferred to an NMR tube to form 120 A
17:31 Obtained HNMR of 120A (11min)
17:43 Obtained HNMR of 120A (23min)
17:52 Obtained HNMR of 120A (32min)
17:56 Obtained HNMR of 120A (36min)
18:08 Obtained HNMR of 120A (48min)
18:24 Obtained HNMR of 120A (1h 4min)
18:54 Obtained HNMR of 120A (1h 34min)
19:10 Completed the addition of boc-tryptophan and pentyl isocyanide to give 120B
19:21 Obtained HNMR of 120B (11min)

2007-08-16

10:00 Solid has appeared in the solution of 120B.

2007-08-17

10:00 Although there is some solid visible in the tube, but it may not isolable because of its mere quantity.
14:10 The solution in the NMR tube was shaken vigorously, the solid which had appeared dissolved...thereby allowing an HNMR tobe taken. (18h)